Building the three colormap operators

In simple cases M₁, from eq. (1), is a histogram equalization operator (for contrast adjustment) or only the identity matrix, and M₂ and M₃ represent raising each point in the matrix to a power. Several variations that would result in monochrome colormaps suitable especially for highlighting linear, coherent shapes (fig. 6) can be imagined. If a more complex colormap is desired, the three operators must be constructed by transforming common RGB colormaps to NTSC, with the equation:  

$$\left[ \matrix { Y \cr I \cr Q} \right] = \left[ \matr... ...312 } \right] \ \ \left[ \matrix { R \cr G \cr B} \right]$$ (5)

An example is provided in Figure 1 for Matlab's jet colormap.